VIENTIANE, LAOS — Southeast Asian defense chiefs met Thursday with their counterparts from China, the United States and other nations in Laos for security talks, which come as Beijing’s increasingly assertive stance in its claim to most of the South China Sea is leading to more confrontations. The closed-door talks put U.S. Secretary of Defense Lloyd Austin and Chinese Defense Minister Dong Jun in the same room, a day after Dong refused a request to meet with Austin one-on-one on the sidelines of the ASEAN summit of defense ministers. The U.S. and China have been working to improve frayed military-to-military communications, and Austin said he regretted Dong’s decision, calling it “a setback for the whole region.” A Chinese statement indicated that Beijing was unhappy with U.S. actions related to Taiwan, the self-governing island that China claims. The U.S. recently approved $2 billion in arms sales to Taiwan, including an advanced surface-to-air missile defense system. “The U.S. side cannot undermine China’s core interests on the Taiwan issue while conducting exchanges with the Chinese military as if nothing had happened,” Defense Ministry spokesperson Wu Qian said in a statement posted online Thursday. The ASEAN meetings come as member nations are looking warily toward the change in American administrations at a time of increasing maritime disputes with China. The U.S. has firmly pushed a “free and open Indo-Pacific” policy under outgoing President Joe Biden, and it is not yet clear how the incoming administration of President-elect Donald Trump will address the South China Sea situation. Dong called for resolving issues through dialogue and not provoking disputes or introducing external forces, China’s official Xinhua News Agency reported. South China Sea Beijing believes that U.S. backing has emboldened the Philippines to act more assertively in its South China Sea disputes with China. Other nations attending the ASEAN meeting from outside Southeast Asia include Japan, South Korea, India, Russia, Australia and New Zealand. The meetings with the ASEAN dialogue partners were also expected to address tensions in the Korean Peninsula, the Russia-Ukraine war and wars in the Middle East. Before heading to Laos, Austin concluded meetings in Australia with officials there and with Japan’s defense minister. They pledged to support ASEAN and expressed their “serious concern about destabilizing actions in the East and South China Seas, including dangerous conduct by the People’s Republic of China against Philippines and other coastal state vessels.” Along with the Philippines, ASEAN members Vietnam, Malaysia and Brunei have competing claims with China in the South China Sea, which Beijing claims almost entirely as its own territory. Indonesia, Thailand, Singapore, Myanmar, Cambodia and Laos are the other members of ASEAN, which stands for Association of Southeast Asian Nations. As China has grown more assertive in pushing its territorial claims in recent years, it and ASEAN have been negotiating a code of conduct to govern behavior in the sea. Progress has been slow. Officials have agreed to try to complete the code by 2026, but talks have been hampered by thorny issues, including disagreements over whether the pact should be binding. Chinese and Philippine vessels have clashed repeatedly this year, and Vietnam in October charged that Chinese forces assaulted its fishermen in disputed areas in the South China Sea. China has also sent patrol vessels to areas that Indonesia and Malaysia claim as their exclusive economic zones. Myanmar crisis Another thorny regional issue is the civil war and humanitarian crisis in ASEAN member Myanmar. The group’s credibility has been severely tested by the war in Myanmar, where the army ousted an elected government in 2021 and fighting has continued with pro-democracy guerillas and ethnic rebels. More than a year into an offensive initiated by three militias and joined by other resistance groups, observers estimate the military controls less than half the country. Myanmar military rulers have been barred from ASEAN meetings since late 2021, but this year the country has been represented by high-level bureaucrats, including at the summit in October. At the defense meetings, the country is represented by Zaw Naing Win, director of the Defense Ministry’s International Affairs Department.